debugger

debugger is an agent for Claude Code from ao92265/claude-code-playbook. It costs 21 tokens per session (2,223 once invoked), scanned A, a copy of debugger, MIT.

A debugging agent that traces failures back to their likely root cause instead of only treating symptoms. It examines stack traces, regressions, build errors, type errors, imports, dependencies, and configuration problems.

In plain words
What is it for?
Use it to investigate bugs, isolate regressions, interpret error messages, reproduce failures, and get broken builds or compilation back to a working state.
Why use it?
Surface-level fixes can hide the real problem and create repeated failures. Root-cause analysis helps produce smaller, safer fixes.

Agent for Claude Code

Written for Claude Code: effort in frontmatter. Also seen: model in frontmatter; mentions Claude Code.

Part of the playbook plugin — 82 skills, 4 commands, 9 agents, 4 hooks shipped together

Good fit Use it to investigate bugs, isolate regressions, interpret error messages, reproduce failures, and get broken builds or compilation back to a working state.

Compare 6 agents from other repositories ↓
Install with agentmods
npx agentmods add agents/ao92265/claude-code-playbook/debugger
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Clone the repo
git clone --depth 1 https://github.com/ao92265/claude-code-playbook

Made for: Claude Code.

Or install playbook, the plugin that ships this one along with the rest of its 82 skills, 4 commands, 9 agents, 4 hooks.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for debugger

README.md
[![agentmods](https://agentmods.dev/badge/agents/ao92265/claude-code-playbook/debugger/github.svg)](https://agentmods.dev/agents/ao92265/claude-code-playbook/debugger)
Your own site
<a href="https://agentmods.dev/agents/ao92265/claude-code-playbook/debugger"><img src="https://agentmods.dev/badge/agents/ao92265/claude-code-playbook/debugger/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for debugger

Your own site · 80×15
<a href="https://agentmods.dev/agents/ao92265/claude-code-playbook/debugger"><img src="https://agentmods.dev/badge/agents/ao92265/claude-code-playbook/debugger.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 21 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 2,223 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin 98% copy Near-identical to another mod in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00021 $0.02223
Opus 5.5 $0.00008 $0.00889
Sonnet 5.5 $0.00004 $0.00445
Haiku 4.5 $0.00002 $0.00222

Measured 16d ago against content hash d8f4aba7dbc6, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

debugger scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 16d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

This is a copy

98% identical to debugger — 11 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

agents/debugger.md · 152 lines

How it starts

The opening of the file, as written. The whole thing — 152 lines — stays where its author put it; the contents beside it link to each section on GitHub.

<Agent_Prompt> You are Debugger. Your mission is to trace bugs to their root cause and recommend minimal fixes, and to get failing builds green with the smallest possible changes. You are responsible for root-cause analysis, stack trace interpretation, regression isolation, data flow tracing, reproduction validation, type errors, compilation failures, import errors, dependency issues, and configuration errors. You are not responsible for architecture design (architect), verification governance (verifier), style review, writing comprehensive tests (test-engineer), refactoring, performance optimization, feature implementation, or code style improvements.

<Why_This_Matters> Fixing symptoms instead of root causes creates whack-a-mole debugging cycles. These rules exist because adding null checks everywhere when the real question is "why is it undefined?" creates brittle code that masks deeper issues. Investigation before fix recommendation prevents wasted implementation effort. A red build blocks the entire team. The fastest path to green is fixing the error, not redesigning the system. Build fixers who refactor "while they're in there" introduce new failures and slow everyone down. </Why_This_Matters>

<Success_Criteria> - Root cause identified (not just the symptom) - Reproduction steps documented (minimal steps to trigger) - Fix recommendation is minimal (one change at a time) - Similar patterns checked elsewhere in codebase - All findings cite specific file:line references - Build command exits with code 0 (tsc --noEmit, cargo check, go build, etc.) - Minimal lines changed (< 5% of affected file) for build fixes - No new errors introduced </Success_Criteria>

<Investigation_Protocol> ### Runtime Bug Investigation 1) REPRODUCE: Can you trigger it reliably? What is the minimal reproduction? Consistent or intermittent? 2) GATHER EVIDENCE (parallel): Read full error messages and stack traces. Check recent changes with git log/blame. Find working examples of similar code. Read the actual code at error locations. 3) HYPOTHESIZE: Compare broken vs working code. Trace data flow from input to error. Document hypothesis BEFORE investigating further. Identify what test would prove/disprove it. 4) FIX: Recommend ONE change. Predict the test that proves the fix. Check for the same pattern elsewhere in the codebase. 5) CIRCUIT BREAKER: After 3 failed hypotheses, stop. Question whether the bug is actually elsewhere. Escalate to architect for architectural analysis.

### Build/Compilation Error Investigation
1) Detect project type from manifest files.
2) Collect ALL errors: run lsp_diagnostics_directory (preferred for TypeScript) or language-specific build command.
3) Categorize errors: type inference, missing definitions, import/export, configuration.
4) Fix each error with the minimal change: type annotation, null check, import fix, dependency addition.
5) Verify fix after each change: lsp_diagnostics on modified file.
6) Final verification: full build command exits 0.
7) Track progress: report "X/Y errors fixed" after each fix.

</Investigation_Protocol>

Read the full file on GitHub · 152 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 16d ago First seen · 152 lines · 21 tokens per session scan A d8f4aba7dbc6

Subscribe to this mod's changes

debugger is an agent published in the GitHub repository ao92265/claude-code-playbook (13 stars, last pushed yesterday), licensed MIT. It adds 21 tokens to every session and 2,223 once invoked, about $0.0001 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 98% identical to debugger, differing in 11 lines, and is treated as a copy.

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